1. Technical Field
This invention relates to surgical apparatus and procedures in general, and more particularly to surgical apparatus and procedures for reconstructing a ligament.
2. Background of Related Art
A ligament is a piece of fibrous tissue which connects one bone to another. Ligaments are frequently damaged (e.g., detached or torn or ruptured, etc.) as the result of injury and/or accident. A damaged ligament can cause instability, impede proper motion of a joint and cause pain. Various procedures have been developed to repair or replace a damaged ligament. The specific procedure used depends on the particular ligament which is to be restored and on the extent of the damage.
One ligament which is frequently damaged as the result of injury and/or accident is the anterior cruciate ligament (i.e., the ACL). Looking first at FIGS. 1 and 2, it will be seen that the ACL 5 extends between the top of the tibia 10 and the bottom of the femur 15. A damaged ACL can cause instability of the knee joint and cause substantial pain and arthritis. For this reason, ACL reconstruction is a common procedure with more than 100,000 cases being performed in the United States annually.
Various procedures have been developed to restore and/or reconstruct a damaged ACL through a graft ligament replacement. Traditionally, this procedure is performed utilizing a trans-tibial approach. In this approach, a bone tunnel 20 (FIG. 3) is first drilled up through tibia 10. Tibial tunnel 20 is then used to access the interior of the knee joint, and it is from tibial tunnel 20 that the position of a femoral tunnel 25 is determined. In this respect, it should be appreciated that the proper positioning of femoral tunnel 25 is important and that numerous guides have been designed to ensure that tibial tunnel 20 is correctly positioned in order to properly position the resulting femoral tunnel 25.
Looking next at FIGS. 4, 5 and 6, simple tibial tunnel positioning guides generally consist of a hooked tip that may be positioned along the ACL footprint on the tibia at a position chosen by the surgeon. Other tibial tunnel positioning guides are more constraining, in order to attempt to obtain a more reliable and reproducible position for the tibial tunnel. As shown in FIG. 7, some other tibial tunnel positioning guides reference the tibial base of the posterior cruciate ligament (“PCL”) (U.S. Pat. No. 5,409,494 to Morgan et al.).
Looking next at FIG. 8, still another guide references the roof of the intercondylar notch, as well as orienting the guide's position relative to the plane of the tibial plateau (U.S. Pat. No. 6,254,605, by Howell et al.). This referencing is done in an attempt to avoid impingement of the femoral roof by the graft ligament.
All of these prior art tibial tunnel positioning guides, while utilizing different referencing points and methods, still share the same overall approach: each of these guides is used to orient the tibial tunnel first, but in a position deemed appropriate for the femoral tunnel, which is thereafter drilled through that tibial tunnel. The limitations of such an approach is that the position of the tibial tunnel is often compromised in order to later drill an appropriate femoral tunnel. This often results in the tibial tunnel being placed in a position which is more posterior and more vertical than is anatomically desired.
Proper placement of the femoral tunnel is imperative in order for the ACL graft to be properly positioned on the femur. However, as a result of using the aforementioned trans-tibial technique, the position of the femoral tunnel is effectively dictated by the position of the first-drilled tibial tunnel. This often results in a femoral tunnel position, and thus, an ACL reconstruction (i.e., graft orientation, etc.) that is less than optimal.
In an attempt to better position the femoral tunnel, surgeons have recently begun utilizing the so-called “medial portal technique” to drill and create the femoral tunnel. An embodiment of a femoral drill guide for use in medial portal techniques is described in commonly owned patent application Ser. No. 12/366,967, the content of which are incorporated by reference in its entirety, and is shown generally as femoral guide 100 in FIG. 4. By drilling the femoral tunnel through the medial portal or an accessory portal, the femoral and tibial tunnels may be drilled independently of one another and, therefore, in a more appropriate
anatomical position. While the medial portal approach greatly improves the ability of the surgeon to more accurately position the femoral tunnel, the older, simple trans-tibial guides are still used by the surgeon to position the tibial tunnel.
Therefore, it would be beneficial to have a device and method for orienting the position of a second-drilled tibial tunnel based on a first-drilled femoral tunnel. It would further be beneficial to have a device and method for positioning a tibial tunnel utilizing the medial portal approach prior to drilling a femoral tunnel.